Still debating whether I liked Ammonite better or not, but I think I might say this one was better objectively. It felt a little bit tighter and more focused. But perhaps it’s not fair to compare the two, as they’re different things. 
This was very good! A bit heavy emotionally. The water treatment leaned technical but wasn’t off putting. One of those books where maybe you’re not happy while reading, but you end up happy you read it. I also think she pulled off suspense quite well!